In an optical fibre communication system, Optical Line Terminator (OLT) may be arranged in the centre office of an access network. The OLT may be configured to transform an electrical signal output from a switcher into an optical signal and then transmit the optical signal, and/or transform an optical signal received from outside into an electrical signal and then transmit the electrical signal to the switcher.
For example, an optical module of an OLT in a 10G Passive Optical Network (PON) may comprise any one or more of the following: an electro-absorption modulated laser (EML), a laser diode driver (LDD), a clock data recovery (CDR), a thermoelectric cooling control (TEC) drive, an electro-absorption biasing circuit (EM Bias-T); an advanced photon detector (APD), a limited amplifier (LIA), an APD boost voltage and Received Signal Strength Indicator (RSSI) sample-and-hold circuit, and a microcontroller unit (MCU).
The optical module may be encapsulated as a 30 pin gold finger (10 gigabit small form factor pluggable, XFP) or a 20 pin gold finger (10 gigabit small form factor pluggable plus, SFP+) and have a configuration of a relative larger volume.